GV2 message contexts.

app/src/main/java/org/thoughtcrime/securesms/conversation/ConversationUpdateItem.java

@@ -103,7 +103,7 @@ public class ConversationUpdateItem extends LinearLayout
     }
 
     if (this.messageRecord != null && messageRecord.isGroupAction()) {
-      GroupUtil.getDescription(getContext(), messageRecord.getBody()).removeObserver(this);
+      GroupUtil.getDescription(getContext(), messageRecord.getBody(), messageRecord.isGroupV2()).removeObserver(this);
     }
 
     this.messageRecord = messageRecord;
@@ -113,7 +113,7 @@ public class ConversationUpdateItem extends LinearLayout
     this.sender.observeForever(this);
 
     if (this.messageRecord != null && messageRecord.isGroupAction()) {
-      GroupUtil.getDescription(getContext(), messageRecord.getBody()).addObserver(this);
+      GroupUtil.getDescription(getContext(), messageRecord.getBody(), messageRecord.isGroupV2()).addObserver(this);
     }
 
     present(messageRecord);
@@ -236,7 +236,7 @@ public class ConversationUpdateItem extends LinearLayout
       sender.removeForeverObserver(this);
     }
     if (this.messageRecord != null && messageRecord.isGroupAction()) {
-      GroupUtil.getDescription(getContext(), messageRecord.getBody()).removeObserver(this);
+      GroupUtil.getDescription(getContext(), messageRecord.getBody(), messageRecord.isGroupV2()).removeObserver(this);
     }
   }
 

app/src/main/java/org/thoughtcrime/securesms/database/MmsDatabase.java

@@ -1137,7 +1137,11 @@ public class MmsDatabase extends MessagingDatabase {
         MessageGroupContext.GroupV2Properties groupV2Properties = outgoingGroupUpdateMessage.requireGroupV2Properties();
         members.addAll(Stream.of(groupV2Properties.getActiveMembers()).map(recipientDatabase::getOrInsertFromUuid).toList());
         if (groupV2Properties.isUpdate()) {
-          members.addAll(Stream.of(groupV2Properties.getPendingMembers()).map(recipientDatabase::getOrInsertFromUuid).toList());
+          members.addAll(Stream.concat(Stream.of(groupV2Properties.getPendingMembers()),
+                                       Stream.of(groupV2Properties.getRemovedMembers()))
+                               .distinct()
+                               .map(recipientDatabase::getOrInsertFromUuid)
+                               .toList());
         }
         members.remove(Recipient.self().getId());
       } else {

app/src/main/java/org/thoughtcrime/securesms/database/SmsDatabase.java

@@ -616,9 +616,14 @@ public class SmsDatabase extends MessagingDatabase {
     } else if (message.isSecureMessage()) {
       type |= Types.SECURE_MESSAGE_BIT;
     } else if (message.isGroup()) {
+      IncomingGroupUpdateMessage incomingGroupUpdateMessage = (IncomingGroupUpdateMessage) message;
+
       type |= Types.SECURE_MESSAGE_BIT;
-      if      (((IncomingGroupUpdateMessage)message).isUpdate()) type |= Types.GROUP_UPDATE_BIT;
+
-      else if (((IncomingGroupUpdateMessage)message).isQuit())   type |= Types.GROUP_QUIT_BIT;
+      if      (incomingGroupUpdateMessage.isGroupV2()) type |= Types.GROUP_V2_BIT | Types.GROUP_UPDATE_BIT;
+      else if (incomingGroupUpdateMessage.isUpdate())  type |= Types.GROUP_UPDATE_BIT;
+      else if (incomingGroupUpdateMessage.isQuit())    type |= Types.GROUP_QUIT_BIT;
+
     } else if (message.isEndSession()) {
       type |= Types.SECURE_MESSAGE_BIT;
       type |= Types.END_SESSION_BIT;

app/src/main/java/org/thoughtcrime/securesms/database/model/DisplayRecord.java

@@ -17,9 +17,10 @@
 package org.thoughtcrime.securesms.database.model;
 
 import android.content.Context;
-import androidx.annotation.NonNull;
 import android.text.SpannableString;
 
+import androidx.annotation.NonNull;
+
 import org.thoughtcrime.securesms.database.MmsSmsColumns;
 import org.thoughtcrime.securesms.database.SmsDatabase;
 import org.thoughtcrime.securesms.recipients.Recipient;
@@ -111,6 +112,10 @@ public abstract class DisplayRecord {
     return SmsDatabase.Types.isGroupUpdate(type);
   }
 
+  public boolean isGroupV2() {
+    return SmsDatabase.Types.isGroupV2(type);
+  }
+
   public boolean isGroupQuit() {
     return SmsDatabase.Types.isGroupQuit(type);
   }

app/src/main/java/org/thoughtcrime/securesms/database/model/MessageRecord.java

@@ -99,7 +99,7 @@ public abstract class MessageRecord extends DisplayRecord {
     if (isGroupUpdate() && isOutgoing()) {
       return new SpannableString(context.getString(R.string.MessageRecord_you_updated_group));
     } else if (isGroupUpdate()) {
-      return new SpannableString(GroupUtil.getDescription(context, getBody()).toString(getIndividualRecipient()));
+      return new SpannableString(GroupUtil.getDescription(context, getBody(), false).toString(getIndividualRecipient()));
     } else if (isGroupQuit() && isOutgoing()) {
       return new SpannableString(context.getString(R.string.MessageRecord_left_group));
     } else if (isGroupQuit()) {

app/src/main/java/org/thoughtcrime/securesms/groups/GroupManagerV1.java

@@ -1,7 +1,6 @@
 package org.thoughtcrime.securesms.groups;
 
 import android.content.Context;
-import android.graphics.Bitmap;
 import android.net.Uri;
 
 import androidx.annotation.NonNull;
@@ -30,8 +29,6 @@ import org.thoughtcrime.securesms.recipients.Recipient;
 import org.thoughtcrime.securesms.recipients.RecipientId;
 import org.thoughtcrime.securesms.recipients.RecipientUtil;
 import org.thoughtcrime.securesms.sms.MessageSender;
-import org.thoughtcrime.securesms.util.BitmapUtil;
-import org.thoughtcrime.securesms.util.GroupUtil;
 import org.thoughtcrime.securesms.util.MediaUtil;
 import org.whispersystems.libsignal.util.guava.Optional;
 import org.whispersystems.signalservice.internal.push.SignalServiceProtos.GroupContext;
@@ -154,7 +151,7 @@ final class GroupManagerV1 {
   static boolean leaveGroup(@NonNull Context context, @NonNull GroupId.V1 groupId) {
     Recipient                            groupRecipient = Recipient.externalGroup(context, groupId);
     long                                 threadId       = DatabaseFactory.getThreadDatabase(context).getThreadIdFor(groupRecipient);
-    Optional<OutgoingGroupUpdateMessage> leaveMessage   = GroupUtil.createGroupLeaveMessage(context, groupRecipient);
+    Optional<OutgoingGroupUpdateMessage> leaveMessage   = createGroupLeaveMessage(context, groupId, groupRecipient);
 
     if (threadId != -1 && leaveMessage.isPresent()) {
       try {
@@ -180,7 +177,7 @@ final class GroupManagerV1 {
     if (DatabaseFactory.getGroupDatabase(context).isActive(groupId)) {
       Recipient                            groupRecipient = Recipient.externalGroup(context, groupId);
       long                                 threadId       = DatabaseFactory.getThreadDatabase(context).getThreadIdFor(groupRecipient);
-      Optional<OutgoingGroupUpdateMessage> leaveMessage   = GroupUtil.createGroupLeaveMessage(context, groupRecipient);
+      Optional<OutgoingGroupUpdateMessage> leaveMessage   = createGroupLeaveMessage(context, groupId, groupRecipient);
 
       if (threadId != -1 && leaveMessage.isPresent()) {
         ApplicationDependencies.getJobManager().add(LeaveGroupJob.create(groupRecipient));
@@ -210,4 +207,32 @@ final class GroupManagerV1 {
     OutgoingExpirationUpdateMessage outgoingMessage = new OutgoingExpirationUpdateMessage(recipient, System.currentTimeMillis(), expirationTime * 1000L);
     MessageSender.send(context, outgoingMessage, threadId, false, null);
   }
+
+  @WorkerThread
+  private static Optional<OutgoingGroupUpdateMessage> createGroupLeaveMessage(@NonNull Context context,
+                                                                              @NonNull GroupId.V1 groupId,
+                                                                              @NonNull Recipient groupRecipient)
+  {
+    GroupDatabase groupDatabase = DatabaseFactory.getGroupDatabase(context);
+
+    if (!groupDatabase.isActive(groupId)) {
+      Log.w(TAG, "Group has already been left.");
+      return Optional.absent();
+    }
+
+    GroupContext groupContext = GroupContext.newBuilder()
+                                            .setId(ByteString.copyFrom(groupId.getDecodedId()))
+                                            .setType(GroupContext.Type.QUIT)
+                                            .build();
+
+    return Optional.of(new OutgoingGroupUpdateMessage(groupRecipient,
+                                                      groupContext,
+                                                      null,
+                                                      System.currentTimeMillis(),
+                                                      0,
+                                                      false,
+                                                      null,
+                                                      Collections.emptyList(),
+                                                      Collections.emptyList()));
+  }
 }

app/src/main/java/org/thoughtcrime/securesms/groups/v2/processing/GroupsV2StateProcessor.java

@@ -7,13 +7,16 @@ import androidx.annotation.Nullable;
 import androidx.annotation.WorkerThread;
 
 import org.signal.storageservice.protos.groups.local.DecryptedGroup;
+import org.signal.storageservice.protos.groups.local.DecryptedGroupChange;
 import org.signal.zkgroup.VerificationFailedException;
 import org.signal.zkgroup.groups.GroupMasterKey;
 import org.signal.zkgroup.groups.GroupSecretParams;
+import org.signal.zkgroup.util.UUIDUtil;
 import org.thoughtcrime.securesms.database.DatabaseFactory;
 import org.thoughtcrime.securesms.database.GroupDatabase;
 import org.thoughtcrime.securesms.database.MmsDatabase;
 import org.thoughtcrime.securesms.database.RecipientDatabase;
+import org.thoughtcrime.securesms.database.SmsDatabase;
 import org.thoughtcrime.securesms.database.model.databaseprotos.DecryptedGroupV2Context;
 import org.thoughtcrime.securesms.dependencies.ApplicationDependencies;
 import org.thoughtcrime.securesms.groups.GroupId;
@@ -29,10 +32,14 @@ import org.thoughtcrime.securesms.mms.MmsException;
 import org.thoughtcrime.securesms.mms.OutgoingGroupUpdateMessage;
 import org.thoughtcrime.securesms.recipients.Recipient;
 import org.thoughtcrime.securesms.recipients.RecipientId;
+import org.thoughtcrime.securesms.sms.IncomingGroupUpdateMessage;
+import org.thoughtcrime.securesms.sms.IncomingTextMessage;
+import org.whispersystems.libsignal.util.guava.Optional;
 import org.whispersystems.signalservice.api.groupsv2.DecryptedGroupHistoryEntry;
 import org.whispersystems.signalservice.api.groupsv2.DecryptedGroupUtil;
 import org.whispersystems.signalservice.api.groupsv2.GroupsV2Api;
 import org.whispersystems.signalservice.api.groupsv2.InvalidGroupStateException;
+import org.whispersystems.signalservice.api.util.UuidUtil;
 import org.whispersystems.signalservice.internal.push.exceptions.NotInGroupException;
 
 import java.io.IOException;
@@ -132,7 +139,14 @@ public final class GroupsV2StateProcessor {
         return new GroupUpdateResult(GroupState.GROUP_CONSISTENT_OR_AHEAD, null);
       }
 
-      GlobalGroupState        inputGroupState         = queryServer();
+      GlobalGroupState inputGroupState;
+      try {
+        inputGroupState = queryServer();
+      } catch (GroupNotAMemberException e) {
+        Log.w(TAG, "Unable to query server for group " + groupId + " server says we're not in group, inserting leave message");
+        insertGroupLeave();
+        throw e;
+      }
       AdvanceGroupStateResult advanceGroupStateResult = GroupStateMapper.partiallyAdvanceGroupState(inputGroupState, revision);
       DecryptedGroup          newLocalState           = advanceGroupStateResult.getNewGlobalGroupState().getLocalState();
 
@@ -152,6 +166,49 @@ public final class GroupsV2StateProcessor {
       return new GroupUpdateResult(GroupState.GROUP_UPDATED, newLocalState);
     }
 
+    private void insertGroupLeave() {
+      if (!groupDatabase.isActive(groupId)) {
+        Log.w(TAG, "Group has already been left.");
+        return;
+      }
+
+      Recipient      groupRecipient = Recipient.externalGroup(context, groupId);
+      UUID           selfUuid       = Recipient.self().getUuid().get();
+      DecryptedGroup decryptedGroup = groupDatabase.requireGroup(groupId)
+                                                   .requireV2GroupProperties()
+                                                   .getDecryptedGroup();
+
+      DecryptedGroup       simulatedGroupState  = DecryptedGroupUtil.removeMember(decryptedGroup, selfUuid, decryptedGroup.getVersion() + 1);
+      DecryptedGroupChange simulatedGroupChange = DecryptedGroupChange.newBuilder()
+                                                                      .setEditor(UuidUtil.toByteString(UuidUtil.UNKNOWN_UUID))
+                                                                      .setVersion(simulatedGroupState.getVersion())
+                                                                      .addDeleteMembers(UuidUtil.toByteString(selfUuid))
+                                                                      .build();
+
+      DecryptedGroupV2Context    decryptedGroupV2Context = GroupProtoUtil.createDecryptedGroupV2Context(masterKey, simulatedGroupState, simulatedGroupChange);
+      OutgoingGroupUpdateMessage leaveMessage            = new OutgoingGroupUpdateMessage(groupRecipient,
+                                                                                          decryptedGroupV2Context,
+                                                                                          null,
+                                                                                          System.currentTimeMillis(),
+                                                                                          0,
+                                                                                          false,
+                                                                                          null,
+                                                                                          Collections.emptyList(),
+                                                                                          Collections.emptyList());
+
+      try {
+        MmsDatabase mmsDatabase = DatabaseFactory.getMmsDatabase(context);
+        long        threadId    = DatabaseFactory.getThreadDatabase(context).getThreadIdFor(groupRecipient);
+        long        id          = mmsDatabase.insertMessageOutbox(leaveMessage, threadId, false, null);
+        mmsDatabase.markAsSent(id, true);
+      } catch (MmsException e) {
+        Log.w(TAG, "Failed to insert leave message.", e);
+      }
+
+      groupDatabase.setActive(groupId, false);
+      groupDatabase.remove(groupId, Recipient.self().getId());
+    }
+
     /**
      * @return true iff group exists locally and is at least the specified revision.
      */
@@ -252,17 +309,29 @@ public final class GroupsV2StateProcessor {
     }
 
     private void storeMessage(@NonNull DecryptedGroupV2Context decryptedGroupV2Context, long timestamp) {
-      try {
+      UUID editor = DecryptedGroupUtil.editorUuid(decryptedGroupV2Context.getChange());
-        MmsDatabase                mmsDatabase     = DatabaseFactory.getMmsDatabase(context);
+      boolean outgoing = Recipient.self().getUuid().get().equals(editor);
-        RecipientId                recipientId     = recipientDatabase.getOrInsertFromGroupId(groupId);
-        Recipient                  recipient       = Recipient.resolved(recipientId);
-        OutgoingGroupUpdateMessage outgoingMessage = new OutgoingGroupUpdateMessage(recipient, decryptedGroupV2Context, null, timestamp, 0, false, null, Collections.emptyList(), Collections.emptyList());
-        long                       threadId        = DatabaseFactory.getThreadDatabase(context).getThreadIdFor(recipient);
-        long                       messageId       = mmsDatabase.insertMessageOutbox(outgoingMessage, threadId, false, null);
 
-        mmsDatabase.markAsSent(messageId, true);
+      if (outgoing) {
-      } catch (MmsException e) {
+        try {
-        Log.w(TAG, e);
+          MmsDatabase                mmsDatabase     = DatabaseFactory.getMmsDatabase(context);
+          RecipientId                recipientId     = recipientDatabase.getOrInsertFromGroupId(groupId);
+          Recipient                  recipient       = Recipient.resolved(recipientId);
+          OutgoingGroupUpdateMessage outgoingMessage = new OutgoingGroupUpdateMessage(recipient, decryptedGroupV2Context, null, timestamp, 0, false, null, Collections.emptyList(), Collections.emptyList());
+          long                       threadId        = DatabaseFactory.getThreadDatabase(context).getThreadIdFor(recipient);
+          long                       messageId       = mmsDatabase.insertMessageOutbox(outgoingMessage, threadId, false, null);
+
+          mmsDatabase.markAsSent(messageId, true);
+        } catch (MmsException e) {
+          Log.w(TAG, e);
+        }
+      } else {
+        SmsDatabase                smsDatabase  = DatabaseFactory.getSmsDatabase(context);
+        RecipientId                sender       = Recipient.externalPush(context, editor, null).getId();
+        IncomingTextMessage        incoming     = new IncomingTextMessage(sender, -1, timestamp, timestamp, "", Optional.of(groupId), 0, false);
+        IncomingGroupUpdateMessage groupMessage = new IncomingGroupUpdateMessage(incoming, decryptedGroupV2Context);
+
+        smsDatabase.insertMessageInbox(groupMessage);
       }
     }
   }

app/src/main/java/org/thoughtcrime/securesms/jobs/PushGroupSendJob.java

@@ -58,7 +58,6 @@ import java.io.IOException;
 import java.util.Collections;
 import java.util.List;
 import java.util.Set;
-import java.util.UUID;
 import java.util.concurrent.TimeUnit;
 
 public class PushGroupSendJob extends PushSendJob {
@@ -167,10 +166,9 @@ public class PushGroupSendJob extends PushSendJob {
 
       List<RecipientId> target;
 
-      if      (filterRecipient != null)                                                        target = Collections.singletonList(Recipient.resolved(filterRecipient).getId());
+      if      (filterRecipient != null)            target = Collections.singletonList(Recipient.resolved(filterRecipient).getId());
-      else if (!existingNetworkFailures.isEmpty())                                             target = Stream.of(existingNetworkFailures).map(nf -> nf.getRecipientId(context)).toList();
+      else if (!existingNetworkFailures.isEmpty()) target = Stream.of(existingNetworkFailures).map(nf -> nf.getRecipientId(context)).toList();
-      else if (groupRecipient.isPushV2Group() && message instanceof OutgoingGroupUpdateMessage) target = getGroupMessageV2Recipients((OutgoingGroupUpdateMessage) message);
+      else                                         target = getGroupMessageRecipients(groupRecipient.requireGroupId(), messageId);
-      else                                                                                     target = getGroupMessageRecipients(groupRecipient.requireGroupId(), messageId);
 
       List<SendMessageResult>   results                  = deliver(message, groupRecipient, target);
       List<NetworkFailure>      networkFailures          = Stream.of(results).filter(SendMessageResult::isNetworkFailure).map(result -> new NetworkFailure(Recipient.externalPush(context, result.getAddress()).getId())).toList();
@@ -330,24 +328,20 @@ public class PushGroupSendJob extends PushSendJob {
   private @NonNull List<RecipientId> getGroupMessageRecipients(@NonNull GroupId groupId, long messageId) {
     List<GroupReceiptInfo> destinations = DatabaseFactory.getGroupReceiptDatabase(context).getGroupReceiptInfo(messageId);
 
-    if (!destinations.isEmpty()) return Stream.of(destinations).map(GroupReceiptInfo::getRecipientId).toList();
+    if (!destinations.isEmpty()) {
+      return Stream.of(destinations).map(GroupReceiptInfo::getRecipientId).toList();
+    }
 
-    List<Recipient> members = DatabaseFactory.getGroupDatabase(context).getGroupMembers(groupId, GroupDatabase.MemberSet.FULL_MEMBERS_EXCLUDING_SELF);
+    List<RecipientId> members = Stream.of(DatabaseFactory.getGroupDatabase(context)
-    return Stream.of(members).map(Recipient::getId).toList();
+                                                         .getGroupMembers(groupId, GroupDatabase.MemberSet.FULL_MEMBERS_EXCLUDING_SELF))
-  }
+                                      .map(Recipient::getId)
+                                      .toList();
 
-  private @NonNull List<RecipientId> getGroupMessageV2Recipients(@NonNull OutgoingGroupUpdateMessage message) {
+    if (members.size() > 0) {
-    UUID                                  selfUUId          = Recipient.self().getUuid().get();
+      Log.w(TAG, "No destinations found for group message " + groupId + " using current group membership");
-    MessageGroupContext.GroupV2Properties groupV2Properties = message.requireGroupV2Properties();
+    }
-    boolean                               includePending    = groupV2Properties.isUpdate();
+    
-
+    return members;
-    return Stream.concat(Stream.of(groupV2Properties.getActiveMembers()),
-                         includePending ? Stream.of(groupV2Properties.getPendingMembers()) : Stream.empty())
-                 .filterNot(selfUUId::equals)
-                 .distinct()
-                 .map(uuid -> Recipient.externalPush(context, uuid, null))
-                 .map(Recipient::getId)
-                 .toList();
   }
 
   public static class Factory implements Job.Factory<PushGroupSendJob> {

app/src/main/java/org/thoughtcrime/securesms/mms/MessageGroupContext.java

@@ -1,19 +1,24 @@
 package org.thoughtcrime.securesms.mms;
 
 import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
 
-import com.annimon.stream.Stream;
+import org.signal.storageservice.protos.groups.local.DecryptedMember;
-
 import org.signal.zkgroup.InvalidInputException;
 import org.signal.zkgroup.groups.GroupMasterKey;
-import org.signal.zkgroup.util.UUIDUtil;
+import org.thoughtcrime.securesms.database.model.databaseprotos.DecryptedGroupV2Context;
+import org.thoughtcrime.securesms.recipients.Recipient;
+import org.thoughtcrime.securesms.recipients.RecipientId;
 import org.thoughtcrime.securesms.util.Base64;
 import org.whispersystems.signalservice.api.groupsv2.DecryptedGroupUtil;
+import org.whispersystems.signalservice.api.util.UuidUtil;
 import org.whispersystems.signalservice.internal.push.SignalServiceProtos.GroupContext;
 import org.whispersystems.signalservice.internal.push.SignalServiceProtos.GroupContextV2;
-import org.thoughtcrime.securesms.database.model.databaseprotos.DecryptedGroupV2Context;
 
 import java.io.IOException;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.LinkedList;
 import java.util.List;
 import java.util.UUID;
 
@@ -22,9 +27,10 @@ import java.util.UUID;
  */
 public final class MessageGroupContext {
 
-  private final String            encodedGroupContext;
+  @NonNull  private final String            encodedGroupContext;
-  private final GroupV1Properties groupV1;
+  @NonNull  private final GroupProperties   group;
-  private final GroupV2Properties groupV2;
+  @Nullable private final GroupV1Properties groupV1;
+  @Nullable private final GroupV2Properties groupV2;
 
   public MessageGroupContext(@NonNull String encodedGroupContext, boolean v2)
       throws IOException
@@ -33,9 +39,11 @@ public final class MessageGroupContext {
     if (v2) {
       this.groupV1 = null;
       this.groupV2 = new GroupV2Properties(DecryptedGroupV2Context.parseFrom(Base64.decode(encodedGroupContext)));
+      this.group   = groupV2;
     } else {
       this.groupV1 = new GroupV1Properties(GroupContext.parseFrom(Base64.decode(encodedGroupContext)));
       this.groupV2 = null;
+      this.group   = groupV1;
     }
   }
 
@@ -43,12 +51,14 @@ public final class MessageGroupContext {
     this.encodedGroupContext = Base64.encodeBytes(group.toByteArray());
     this.groupV1             = new GroupV1Properties(group);
     this.groupV2             = null;
+    this.group               = groupV1;
   }
 
   public MessageGroupContext(@NonNull DecryptedGroupV2Context group) {
     this.encodedGroupContext = Base64.encodeBytes(group.toByteArray());
     this.groupV1             = null;
     this.groupV2             = new GroupV2Properties(group);
+    this.group               = groupV2;
   }
   
   public @NonNull GroupV1Properties requireGroupV1Properties() {
@@ -73,7 +83,20 @@ public final class MessageGroupContext {
     return encodedGroupContext;
   }
 
-  public static class GroupV1Properties {
+  public String getName() {
+    return group.getName();
+  }
+
+  public List<RecipientId> getMembersListExcludingSelf() {
+    return group.getMembersListExcludingSelf();
+  }
+
+  interface GroupProperties {
+    @NonNull String getName();
+    @NonNull List<RecipientId> getMembersListExcludingSelf();
+  }
+
+  public static class GroupV1Properties implements GroupProperties {
 
     private final GroupContext groupContext;
 
@@ -92,9 +115,32 @@ public final class MessageGroupContext {
     public boolean isUpdate() {
       return groupContext.getType().getNumber() == GroupContext.Type.UPDATE_VALUE;
     }
+
+    @Override
+    public @NonNull String getName() {
+      return groupContext.getName();
+    }
+
+    @Override
+    public @NonNull List<RecipientId> getMembersListExcludingSelf() {
+      List<GroupContext.Member> membersList = groupContext.getMembersList();
+      if (membersList.isEmpty()) {
+        return Collections.emptyList();
+      } else {
+        LinkedList<RecipientId> members = new LinkedList<>();
+
+        for (GroupContext.Member member : membersList) {
+          RecipientId recipient = RecipientId.from(UuidUtil.parseOrNull(member.getUuid()), member.getE164());
+          if (!Recipient.self().getId().equals(recipient)) {
+            members.add(recipient);
+          }
+        }
+        return members;
+      }
+    }
   }
 
-  public static class GroupV2Properties {
+  public static class GroupV2Properties implements GroupProperties {
 
     private final DecryptedGroupV2Context decryptedGroupV2Context;
     private final GroupContextV2          groupContext;
@@ -126,9 +172,32 @@ public final class MessageGroupContext {
       return DecryptedGroupUtil.pendingToUuidList(decryptedGroupV2Context.getGroupState().getPendingMembersList());
     }
 
+    public @NonNull List<UUID> getRemovedMembers() {
+      return DecryptedGroupUtil.removedMembersUuidList(decryptedGroupV2Context.getChange());
+    }
+
     public boolean isUpdate() {
       // The group context is only stored on update messages.
       return true;
     }
+
+    @Override
+    public @NonNull String getName() {
+      return decryptedGroupV2Context.getGroupState().getTitle();
+    }
+
+    @Override
+    public @NonNull List<RecipientId> getMembersListExcludingSelf() {
+      List<RecipientId> members = new ArrayList<>(decryptedGroupV2Context.getGroupState().getMembersCount());
+
+      for (DecryptedMember member : decryptedGroupV2Context.getGroupState().getMembersList()) {
+        RecipientId recipient = RecipientId.from(UuidUtil.fromByteString(member.getUuid()), null);
+        if (!Recipient.self().getId().equals(recipient)) {
+          members.add(recipient);
+        }
+      }
+
+      return members;
+    }
   }
 }

app/src/main/java/org/thoughtcrime/securesms/recipients/ui/bottomsheet/RecipientDialogRepository.java

@@ -42,13 +42,11 @@ final class RecipientDialogRepository {
     this.groupId     = groupId;
   }
 
-  @NonNull
+  @NonNull RecipientId getRecipientId() {
-  RecipientId getRecipientId() {
     return recipientId;
   }
 
-  @Nullable
+  @Nullable GroupId getGroupId() {
-  GroupId getGroupId() {
     return groupId;
   }
 

app/src/main/java/org/thoughtcrime/securesms/sms/IncomingGroupUpdateMessage.java

@@ -1,13 +1,24 @@
 package org.thoughtcrime.securesms.sms;
 
+import org.thoughtcrime.securesms.database.model.databaseprotos.DecryptedGroupV2Context;
+import org.thoughtcrime.securesms.mms.MessageGroupContext;
+
 import static org.whispersystems.signalservice.internal.push.SignalServiceProtos.GroupContext;
 
 public final class IncomingGroupUpdateMessage extends IncomingTextMessage {
 
-  private final GroupContext groupContext;
+  private final MessageGroupContext groupContext;
 
   public IncomingGroupUpdateMessage(IncomingTextMessage base, GroupContext groupContext, String body) {
-    super(base, body);
+    this(base, new MessageGroupContext(groupContext));
+  }
+
+  public IncomingGroupUpdateMessage(IncomingTextMessage base, DecryptedGroupV2Context groupV2Context) {
+    this(base, new MessageGroupContext(groupV2Context));
+  }
+
+  public IncomingGroupUpdateMessage(IncomingTextMessage base, MessageGroupContext groupContext) {
+    super(base, groupContext.getEncodedGroupContext());
     this.groupContext = groupContext;
   }
 
@@ -17,11 +28,15 @@ public final class IncomingGroupUpdateMessage extends IncomingTextMessage {
   }
 
   public boolean isUpdate() {
-    return groupContext.getType().getNumber() == GroupContext.Type.UPDATE_VALUE;
+    return groupContext.isV2Group() || groupContext.requireGroupV1Properties().isUpdate();
+  }
+
+  public boolean isGroupV2() {
+    return groupContext.isV2Group();
   }
 
   public boolean isQuit() {
-    return groupContext.getType().getNumber() == GroupContext.Type.QUIT_VALUE;
+    return !groupContext.isV2Group() && groupContext.requireGroupV1Properties().isQuit();
   }
 
 }

app/src/main/java/org/thoughtcrime/securesms/util/GroupUtil.java

@@ -6,15 +6,13 @@ import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import androidx.annotation.WorkerThread;
 
-import com.google.protobuf.ByteString;
-
 import org.thoughtcrime.securesms.R;
 import org.thoughtcrime.securesms.database.DatabaseFactory;
 import org.thoughtcrime.securesms.database.GroupDatabase;
 import org.thoughtcrime.securesms.groups.BadGroupIdException;
 import org.thoughtcrime.securesms.groups.GroupId;
 import org.thoughtcrime.securesms.logging.Log;
-import org.thoughtcrime.securesms.mms.OutgoingGroupUpdateMessage;
+import org.thoughtcrime.securesms.mms.MessageGroupContext;
 import org.thoughtcrime.securesms.recipients.Recipient;
 import org.thoughtcrime.securesms.recipients.RecipientForeverObserver;
 import org.thoughtcrime.securesms.recipients.RecipientId;
@@ -23,15 +21,10 @@ import org.whispersystems.signalservice.api.messages.SignalServiceDataMessage;
 import org.whispersystems.signalservice.api.messages.SignalServiceGroup;
 import org.whispersystems.signalservice.api.messages.SignalServiceGroupContext;
 import org.whispersystems.signalservice.api.messages.SignalServiceGroupV2;
-import org.whispersystems.signalservice.api.util.UuidUtil;
 
 import java.io.IOException;
-import java.util.Collections;
-import java.util.LinkedList;
 import java.util.List;
 
-import static org.whispersystems.signalservice.internal.push.SignalServiceProtos.GroupContext;
-
 public final class GroupUtil {
 
   private GroupUtil() {
@@ -74,34 +67,13 @@ public final class GroupUtil {
     return Optional.absent();
   }
 
-  @WorkerThread
+  public static @NonNull GroupDescription getDescription(@NonNull Context context, @Nullable String encodedGroup, boolean isV2) {
-  public static Optional<OutgoingGroupUpdateMessage> createGroupLeaveMessage(@NonNull Context context, @NonNull Recipient groupRecipient) {
-    GroupId       encodedGroupId = groupRecipient.requireGroupId();
-    GroupDatabase groupDatabase  = DatabaseFactory.getGroupDatabase(context);
-
-    if (!groupDatabase.isActive(encodedGroupId)) {
-      Log.w(TAG, "Group has already been left.");
-      return Optional.absent();
-    }
-
-    ByteString decodedGroupId = ByteString.copyFrom(encodedGroupId.getDecodedId());
-
-    GroupContext groupContext = GroupContext.newBuilder()
-                                            .setId(decodedGroupId)
-                                            .setType(GroupContext.Type.QUIT)
-                                            .build();
-
-    return Optional.of(new OutgoingGroupUpdateMessage(groupRecipient, groupContext, null, System.currentTimeMillis(), 0, false, null, Collections.emptyList(), Collections.emptyList()));
-  }
-
-
-  public static @NonNull GroupDescription getDescription(@NonNull Context context, @Nullable String encodedGroup) {
     if (encodedGroup == null) {
       return new GroupDescription(context, null);
     }
 
     try {
-      GroupContext  groupContext = GroupContext.parseFrom(Base64.decode(encodedGroup));
+      MessageGroupContext groupContext = new MessageGroupContext(encodedGroup, isV2);
       return new GroupDescription(context, groupContext);
     } catch (IOException e) {
       Log.w(TAG, e);
@@ -129,25 +101,19 @@ public final class GroupUtil {
 
   public static class GroupDescription {
 
-    @NonNull  private final Context           context;
+    @NonNull  private final Context             context;
-    @Nullable private final GroupContext      groupContext;
+    @Nullable private final MessageGroupContext groupContext;
-    @Nullable private final List<RecipientId> members;
+    @Nullable private final List<RecipientId>   members;
 
-    GroupDescription(@NonNull Context context, @Nullable GroupContext groupContext) {
+    GroupDescription(@NonNull Context context, @Nullable MessageGroupContext groupContext) {
       this.context      = context.getApplicationContext();
       this.groupContext = groupContext;
 
-      if (groupContext == null || groupContext.getMembersList().isEmpty()) {
+      if (groupContext == null) {
         this.members = null;
       } else {
-        this.members = new LinkedList<>();
+        List<RecipientId> membersList = groupContext.getMembersListExcludingSelf();
-
+        this.members = membersList.isEmpty() ? null : membersList;
-        for (GroupContext.Member member : groupContext.getMembersList()) {
-          RecipientId recipientId = RecipientId.from(UuidUtil.parseOrNull(member.getUuid()), member.getE164());
-          if (!recipientId.equals(Recipient.self().getId())) {
-            this.members.add(recipientId);
-          }
-        }
       }
     }
 

app/src/main/res/values/strings.xml

@@ -678,6 +678,7 @@
     <string name="MediaRepository_all_media">All media</string>
 
     <!-- MessageRecord -->
+    <string name="MessageRecord_unknown">Unknown</string>
     <string name="MessageRecord_message_encrypted_with_a_legacy_protocol_version_that_is_no_longer_supported">Received a message encrypted using an old version of Signal that is no longer supported. Please ask the sender to update to the most recent version and resend the message.</string>
     <string name="MessageRecord_left_group">You have left the group.</string>
     <string name="MessageRecord_you_updated_group">You updated the group.</string>
@@ -695,6 +696,9 @@
     <string name="MessageRecord_s_set_disappearing_message_time_to_s">%1$s set the disappearing message timer to %2$s.</string>
 
     <!-- GV2 specific -->
+    <string name="MessageRecord_you_created_the_group">You created the group.</string>
+    <string name="MessageRecord_group_updated">Group updated.</string>
+
     <!-- GV2 member additions -->
     <string name="MessageRecord_you_added_s">You added %1$s.</string>
     <string name="MessageRecord_s_added_s">%1$s added %2$s.</string>

libsignal/service/src/main/java/org/whispersystems/signalservice/api/groupsv2/DecryptedGroupUtil.java

@@ -63,12 +63,26 @@ public final class DecryptedGroupUtil {
     return uuidList;
   }
 
+  public static ArrayList<UUID> removedMembersUuidList(DecryptedGroupChange groupChange) {
+    ArrayList<UUID> uuidList = new ArrayList<>(groupChange.getDeleteMembersCount());
+
+    for (ByteString member : groupChange.getDeleteMembersList()) {
+      uuidList.add(toUuid(member));
+    }
+
+    return uuidList;
+  }
+
   public static UUID toUuid(DecryptedMember member) {
-    return UUIDUtil.deserialize(member.getUuid().toByteArray());
+    return toUuid(member.getUuid());
   }
 
   public static UUID toUuid(DecryptedPendingMember member) {
-    return UUIDUtil.deserialize(member.getUuid().toByteArray());
+    return toUuid(member.getUuid());
+  }
+
+  private static UUID toUuid(ByteString member) {
+    return UUIDUtil.deserialize(member.toByteArray());
   }
 
   /**
@@ -90,6 +104,16 @@ public final class DecryptedGroupUtil {
     return Optional.absent();
   }
 
+  public static Optional<DecryptedMember> firstMember(Collection<DecryptedMember> members) {
+    Iterator<DecryptedMember> iterator = members.iterator();
+
+    if (iterator.hasNext()) {
+      return Optional.of(iterator.next());
+    } else {
+      return Optional.absent();
+    }
+  }
+
   public static Optional<DecryptedPendingMember> findPendingByUuid(Collection<DecryptedPendingMember> members, UUID uuid) {
     ByteString uuidBytes = UuidUtil.toByteString(uuid);